Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/12—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress
  • G01L1/127—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress by using inductive means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/04—Measuring force or stress, in general by measuring elastic deformation of gauges, e.g. of springs
  • G01L1/044—Measuring force or stress, in general by measuring elastic deformation of gauges, e.g. of springs of leaf springs
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
  • G01M5/0016—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings of aircraft wings or blades
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
  • G01M5/0033—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining damage, crack or wear
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
  • G01M5/0041—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
  • G01M5/0091—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by using electromagnetic excitation or detection

Definitions

• the present invention relates to a device for detecting detachment and an assembly for such a device.
• the fields concerned by the invention are, in a non-exhaustive manner, the following fields: all sectors of mechanics in the air with aeronautics, on water and in water with the maritime sector, on land with the land transport, and civil engineering.
• boundary layer When the boundary layer is subjected to an adverse pressure gradient, said boundary layer then undergoes separation.
• the position of the take-off point thus conditions the aerodynamic lift force.
• the stall is therefore the limit of the increase in the force exerted on the profile and composed of the force of lift and drag, depending on the angle of attack. Indeed, the flow velocity is not the same on either side of the profile, inducing a pressure difference between the upper and lower side of said profile. This results in an upward force that is all the more important as the angle of attack is important.
• the stall of the profile then corresponds to the more or less abrupt loss of lift, caused by the separation of the flow on the upper part of the profile.
• the stall leads to the loss of lift because when the profile stalls and is therefore strongly inclined, the angles of attack are greater and the fluid no longer manages to follow the imposed trajectories, which generates a reduction in the deformation of the trajectory. of the fluids, there is then less acceleration of the fluid on the upper face of the profile implying a reduction in the depression. Stall also leads to increased drag, but also to noise pollution, as well as fatigue of the airfoil structure.
• The is composed of three curves: the first graph at the top corresponds to the curve of the evolution of the lift coefficient of the signal from the take-off sensor as a function of the angle of attack on an aerodynamically/hydrodynamically stable profile, the second graph at the middle corresponds to the curve of the evolution of the sliding average of the signal from the lift-off sensor as a function of the angle of attack on an aerodynamically/hydrodynamically stable profile, and the third graph at the bottom corresponds to the sliding standard deviation in function of the angle of attack on an aerodynamically/hydrodynamically stable profile.
• the abscissa of the first curve named Cl for "Lift Coefficient” in Anglo-Saxon terminology (for coefficient of lift in French) and the ordinate named AoA for "Angle of Attack” in Anglo-Saxon terminology (for angle of attack in French).
• the shape of this first curve increases during phase (a) during which the values of the angle of attack are low, then the shape of the first curve continues to grow and stabilizes during phase (b), before grow again during phase (c), after which the first curve disappears during phase (d). From a certain value of the angle of attack, the lift curve no longer appears, meaning that the stall phenomenon has occurred. Indeed, this value of the angle of attack corresponds to the incidence of maximum lift where the depression on the upper part of the profile decreases suddenly following the separation of the air streams and the profile then undergoes stall.
• the abscissa of the second curve corresponds to the value of the theta angle ( ⁇ ) and more particularly to the sliding average of the angle between the tail and the profile, the ordinate corresponds to the value of the angle of offensive.
• the shape of the second curve is rectilinear, stable and with a relatively zero sliding average during phase (a) during which the values of the angle of attack are low, then said shape of the second curve shows an increase followed by a decrease forming a bell-shaped curve during phase (b), before again presenting a bell-shaped curve during phase (c) but having higher values than in phase (b), finally the curve stabilizes again during phase (d) and becomes rectilinear again with a sliding average close to 0.
• the abscissa of the third curve corresponds to the value of sigma and more particularly to the sliding standard deviation of the angle between the tail and the profile, the ordinate corresponds to the value of the angle of attack.
• the shape of the third curve is rectilinear, stable and with a relatively zero sliding average during phase (a) and phase and (b), then said shape of the third curve shows an increase followed by a decrease forming a curve bell-shaped during phase (c) similar to the bell-shaped curve of the second curve during phase (c), finally the curve stabilizes again during phase (d) and becomes rectilinear again with a standard deviation close to 0.
• the average and the sliding standard deviation of the sensor signal make it possible to follow and anticipate the evolution of the lift on the four phases.
• the angle of attack corresponding to the angle formed by the chord connecting the leading edge and the trailing edge, with the speed of the air upstream.
• the greater the angle of attack the more the air streams are deflected by the profile. Once the stall angle is exceeded (d), the aerodynamic performance of the profile is clearly degraded.
• This document describes an invention relating to a wind turbine blade with an electrical stall sensor configured on at least one of said low pressure blade surface or said high pressure blade surface to detect backflow in a stall condition. at said respective pressure surface.
• the peel sensor includes: a power supply; a flap configured pivotally relative to the pressure surface; and a sensor circuit which responds to movement of said flap between said first and second positions and generates a corresponding electrical signal which indicates a peel condition.
• the disadvantage of this type of solution is the loss of performance related to the use of a non-deformable flap which is by nature intrusive for the flow studied.
• the use of a non-deformable flap generates an increase in drag, aerodynamic/hydrodynamic instability, and an early onset of cavitation.
• sensors based on a flap with a pivot axis are difficult to implant one behind the other along the chord, because the disturbances of the sensors upstream promote separation on the sensors downstream.
• the present invention aims to remedy these drawbacks with a totally innovative approach.
• the object of the invention is to provide a device for detecting detachment consisting of a tongue made of flexible and deformable material with no moving part, allowing the detection of detachment, the optimization of the control of the angle of incidence, and the detection of misalignment of wind turbines according to the yaw angle.
• an objective of the invention is to provide such a technique making it possible to dispense with any other complex adjustment system
• the implementation of the present invention allows the integration of the detachment sensor within the profile in order to be the least intrusive possible and not compromise the aerodynamic or hydrodynamic performance of the profile.
• Another object of the invention is to provide such a technique which is inexpensive to implement and which does not require any particular maintenance.
• An object of the invention is to provide such a technique, which can be easily adapted to existing systems.
• a device for detecting separation for an aerodynamic or hydrodynamic profile comprising a monobloc structure remarkable in that it comprises : - a flexible and deformable material tongue from silicone extending between a first end and a second end, the second end being free; - a fixing plate configured to be fixed to a profile, the fixing plate comprises the first end of the flexible and deformable tab, said fixing plate further comprises an electronic card and at least one detachment sensor comprising a magnet generating a electrical signal which indicates a separation value along three orthogonal axes; the electronic card fixed on the fixing plate transmits the electrical signal by a radio transmission system, or by a wired means.
• the separation sensor has the advantage of being perfectly embedded in the aerodynamic/hydrodynamic profile so as not to be intrusive and not to disturb the flow by increasing the drag.
• the tongue itself is made of a flexible and deformable material.
• the present invention makes it possible to broaden the "fields of application and therefore makes it possible to be used for the detection of frost and ice, and the detection of structural defects, as well as the detection of noise pollution.
• the present invention then functions for any type of fluid.
• Said invention is suitable for any type of profile and aerodynamic appendage (aircraft wing, flexible sail, rigid sail, wind turbine blade, helicopter blade, drone blade, fin, empennage, car fin, work of art, ...) and any profile and hydrodynamic appendage (foil, rudder, keel, hull).
• the detachment sensor allows implantation completely integrated into the profile, so there is no modification of the geometry of the profile when there is no detachment.
• the deformable flexible tail sensor allows deployment with an overlap, like a bird's wing.
• Said tail sensor uses the principle of remiges and rectrices, feathers located on the wings and tail and which allow the bird to fly.
• the use of the Hall effect sensor allows better measurement accuracy, reproducibility, and lower power consumption compared to the prior art.
• the present invention has the further advantage of minimizing line breakage of the profile.
• the non-intrusive sensors have a tab made of flexible materials with shape memory, which offers better flexibility and lightness.
• the tab of the present invention is made from silicone with a Shore between 20 and 100.
• the scale of hardness is: Shore A for soft materials, and Shore D for hard materials.
• Shore A or B materials are used, while for hydrodynamic applications where the fluid of interest is water, Shore C or D materials are used.
• the present invention also makes it possible to have a scale implantation, that is to say allowing deployment with covering of flexible and deformable tabs on top of each other, like fish scales or bird feathers.
• the detachment sensor with flexible and deformable tabs therefore uses the principle of remiges and rectrices, feathers located on the wings and tail and which allow the bird to fly.
• the present invention tracks the position of the tail at a solid angle and therefore provides access to the flow direction.
• the present invention is perfectly suited to deformable profiles with variable geometry (thin or thick profiles, inflatable or not) or to rigid profiles.
• the present invention allows a measurement very little subject to the effects of temperature and allows measurement through the walls.
• said device further comprises a battery positioned internally or externally to said device, said battery serving as a power supply and is connected to the electronic card.
• the device forms a one-piece structure composed of three parts: one part comprises the flexible and deformable tab, a second part comprises said fixing plate, a third part comprises a protective shell, said protective shell caps said mounting plate.
• the detachment sensor uses the principle of Hall effect or inductive eddy current electromagnetism.
• the principle of electromagnetism makes it possible to follow the angle of the position of the flexible and deformable tongue with respect to the profile.
• the flexible and deformable tongue moves from a first position, called lowered position, to a second position, called raised position.
• the flexible and deformable tongue is movable from one position to another and makes it possible to follow the detachment of the profile. This is the second end that is free.
• the silicone of the tongue has a Shore between 20 and 100.
• the present invention comprises a plurality of devices for detecting detachment according to one of the preceding claims.
• the plurality of detachment sensors allows better precision and a finer description of the curve of the flexible and deformable tab.
• the described above represents three graphs of the coefficient of lift, the sliding average of the angle between the tail and the profile, and the sliding standard deviation as a function of the angle of attack, explaining the lift-off sensor signal as a function of angle of attack.
• fixing plate is understood to mean being the fixing support of the device.
• the protective shell 20, as well as the fixing plate 22 are made of a vacuum casting polyurethane resin for prototype and technical parts having mechanical properties close to thermoplastic polymers such as acrylonitrile butadiene styrene whose the acronym is ABS and which is a rigid, light and impact-resistant thermoplastic polymer, with a flexural modulus equal to or greater than 2000MPa - Tg 90°C.
• thermoplastic polymers such as acrylonitrile butadiene styrene whose the acronym is ABS and which is a rigid, light and impact-resistant thermoplastic polymer, with a flexural modulus equal to or greater than 2000MPa - Tg 90°C.
• the shows an exploded view of a detachment detection device consisting of: the protective shell 20; the flexible and deformable tongue 21; a magnet 23 adapted to measure the movement of the flexible tab 21; a fixing plate 22 on which is fixed a separation sensor 24, itself fixed on an electronic card, said electronic card 25 makes it possible to connect the Hall effect sensor 24 to a radio transmission system (example 2.4 Ghz) , not shown, or in another embodiment, the signal is transmitted by a wired means, said electronic card 25 is connected to a power supply, not shown, for example an internal battery, or in another embodiment, the sensor detachment 24 is powered by an external source.
• a radio transmission system example 2.4 Ghz
• the fixing plate 22 is glued to the surface of the profile using a two-component polyurethane adhesive glue.
• the sensor 24 makes it possible to follow the shape and the position of the tab 21 with respect to the profile.
• the electronic card 25 is encapsulated in a dielectric resin for perfect sealing.
• the magnet 23 is of the neodymium or ferrite, SmCo, NdFeB or other type.
• SmCo magnets an acronym for samarium-cobalt magnet, is a type of permanent magnet resulting from the alloy of samarium and cobalt.
• NdFeB magnets acronym for neodymium magnet, which are permanent magnets made from the alloy of neodymium, iron and boron.
• the fixing plate 22 covered by the protective shell 20 and the flexible tab 21, remains glued to the profile.
• the flexible and deformable tab 21 is made with a silicone elastomer with a shore of 30 ShA (example: SilasticM, registered trademark).
• a deployment is observed with a covering of the flexible and deformable tongues in the raised position 28 on top of each other.
• the tail of the sensor, corresponding to the flexible and deformable tab bends, and has a raised position 28, due to the separation of the flow on the profile. If the detachment is large enough, it can lead to stalling.
• the arrows around profile 27 correspond to the air flow bypassing profile 27 on either side and which opens at the front of said profile before closing at the rear of said profile.
• the places where the airflow opens and closes correspond to the parting lines positioned just in front of the breakpoints.
• the aerodynamic profile is in an airflow with an appropriate angle of attack, so said profile has a low incidence.
• the airfoil/hydrodynamic profile 27 is in zone (a) of the , its lift changes linearly with the angle of incidence.
• the flow is attached.
• the stopping point is upstream of the separation sensor.
• the position of the lift-off sensor 24 relative to the leading edge is chosen so as to detect a critical angle of attack preceding the stall.
• the arrows around the profile 27, correspond to the flow of air bypassing on either side of the profile 27.
• the state of the air flow forms vortices whose orientation and size constantly fluctuate, and is therefore disordered, corresponding to turbulence.
• the aerodynamic/hydrodynamic profile 27 has left the zone (a) of the to switch to zone (b), (c) or (d).
• the leading edge tongue is in the raised position 30.
• the stopping point has passed the detachment sensor to alert of an imminent detachment.
• The shows a diagram of the physical principle of operation of Hall effect and inductive sensors.
• the bipolar Hall effect sensor annotated C1 sensitive to the north pole (N) and the south pole (S), allows the detection and measurement of magnetic fields, by exploiting the Hall effect, i.e. the appearance of a force proportional to the electromagnetic field when a conductive element is integrated into this electromagnetic field.
• the sensor then generates a voltage allowing the measurement of the current and gives a signal when it is in the presence of a magnetic field which crosses the profile.
• the hall effect sensor is a sensor with three independent axes and provides high accuracy (less than 2%) including temperature compensation.
• the inductive sensor annotated C2, also called eddy current, consists of a coil that generates a magnetic field to allow the detection of variations in the position of the sensor relative to the surface of the metal part (M) placed at the level of the magnetic field.
• the present invention uses a sensor whose electromagnetism principle is Hall effect. According to another embodiment, the present invention uses a sensor whose principle of electromagnetism is inductive.
• the present invention comprises a plurality of devices. Indeed, several magnets 23 and sensors 24 are present within the detachment detection device integrated into the profile, the plurality of said sensors 24 allows better precision.
• the present invention also relates to profiles such as a wind turbine blade.
• profiles such as a wind turbine blade.
• the separation sensors placed on the profile produce a signal transmitted at a sufficiently high frequency to describe the physical phenomenon, said signal which is transmitted by radio transmission to a remote receiver, is itself connected to a processing system, or system of acquisition, allowing the recording of the data, the monitoring in real time the piloting and the enslavement of the profile or the securing of the profile.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Electromagnetism (AREA)
• Measuring Volume Flow (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=76921006

Family Applications (1)

Country Status (5)

Family Cites Families (7)

• 2021
  • 2021-06-23 FR FR2106658A patent/FR3124595B1/fr active Active
• 2022
  • 2022-06-23 US US18/566,595 patent/US12663323B2/en active Active
  • 2022-06-23 CA CA3222123A patent/CA3222123A1/fr active Pending
  • 2022-06-23 WO PCT/EP2022/067116 patent/WO2022268929A1/fr not_active Ceased
  • 2022-06-23 EP EP22734317.5A patent/EP4359748A1/de active Pending

Also Published As

Similar Documents

Legal Events